# -*- coding: UTF-8 -*-  
import pygame

class Ship() :
    def __init__(self, ai_settings, screen) :
        # 初始化飞船并设置其初始化位置
        self.screen = screen
        self.ai_settings = ai_settings

        # 加载飞船图像并获取其外接矩形
        self.image = pygame.image.load('images/ship.png')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        # 将每艘新飞船放在屏幕底部中央
        self.rect.centerx = self.screen_rect.centerx
        self.rect.bottom = self.screen_rect.bottom

        # 在飞船的属性centerx中存储带小数点的数值
        self.center = float(self.rect.centerx)

        # 移动标志
        self.moving_right = False
        self.moving_left = False

    def update(self) :
        # 根据移动标志调整飞船位置
        # 更新飞船的center值，而不是 rect
        if self.moving_right and self.rect.right < self.screen_rect.right:
            self.center += self.ai_settings.ship_speed_factor
        if self.moving_left and self.rect.left > 0 :
            self.center -= self.ai_settings.ship_speed_factor

        # 根据 self.center 更新rect对象
        self.rect.centerx = self.center  

    def blitme(self) :
        # 在指定位置绘制飞船
        
        self.screen.blit(self.image, self.rect)     

 
